Concrete Footing & Wall Calculator

Size concrete for footings and stem walls by length, height, and thickness — with rebar, forms, tools, cost, and a step-by-step plan.

1. Draw your slab
Drag on the grid to draw. Snap shapes together, weld them into one slab, and hover a shape to add a connected piece with the +.

Add shape

Layers

Add a shape or drag on the grid to start your slab.

0'5'10'15'20'25'0'5'10'15'
2 ft
Drag to draw · grid = 1' control joints

Selected shape

Select a shape to edit its size, snap it to others, or weld it into one slab.

Arrows nudge · ⌫ delete · ⌘C / ⌘V copy & paste

2. Answer a few questions
Tell us what the slab is for and we'll suggest a thickness, base, strength, and reinforcement — override anything.

Structural. Poured to undisturbed soil, no gravel base.

Suggested 8"
Sold by the cubic yard; short-load fees apply under ~5 yd.

Vapor barrier

6-mil poly under interior / enclosed slabs

Include tool rental in total

Add advisory rental/buy estimates to the grand total

Extra concrete for spillage and uneven subgrade. 10% is typical.

3. Your plan
Materials, tools, cost, and a step-by-step build plan. Every unit price is editable.

Concrete

1.09 yd³

Footprint

0 ft²

Perimeter

0 ft

Concrete$206

Ready-mix concrete (3000 psi)

1.25 cu yd · Ordered by the cubic yard, delivered. Short-load fees apply under ~5 yd.

Alt: Bagged: 49 x 80 lb bags

$206

Materials$206
Tool rentalnot in total$115
Estimated total$206

From US average prices — click any price to match a local quote. Excludes delivery, permits, and labor.

Tools you'll need

  • WheelbarrowMove and place the concrete.
  • Screed board (straight 2x4)Longer than the form is wide.
  • Bull floatrent ~$55/dayFlatten and close the surface after screeding.
  • Magnesium hand floatDetail work and edges.
  • EdgerRounds and strengthens the slab perimeter.
  • GrooverTools control joints into the wet slab.
  • Shovel, steel rake & margin trowelSpread, pull, and detail the pour.
  • Gloves, eye protection & rubber bootsWet concrete is caustic — cover up.
  • Concrete saw + diamond bladerent ~$60/dayOnly if you cut control joints the next day instead of tooling them wet.

Rental prices show only for specialty gear — skip them if you already own it.

Step-by-step plan

Your build, tracked

Save this plan to Blueprint

Turn your slab into a project with the full step-by-step plan, tool list, and shopping list you can check off as you build — about $206 in materials.

About the concrete footing & wall calculator

Overview

Footings and stem walls are simple rectangular prisms — length times height times thickness — but the reinforcement and form lumber are what people forget to budget. Enter the run, height, and thickness of each footing or wall and this tool returns the concrete volume, the rebar, the form boards and stakes, the tools, and a pour plan.

Add multiple wall segments and combine them with a slab or piers to estimate a whole foundation at once. Prices are editable US averages, so you can dial the total in to local quotes.

How to use this tool
  1. Add a footing/wall element and enter its length and height in feet and thickness in inches.
  2. Add more segments for corners and returns, or a slab on the grid for a monolithic pour.
  3. Pick a rebar size and spacing — continuous footings usually run 2+ horizontal #4 bars.
  4. Review the concrete, rebar, and form lumber, editing unit prices to match local quotes.
  5. Follow the plan to trench, form, reinforce, and pour, then save it to Blueprint.
Frequently asked questions